Category Archives: 4K Studios

I’ve been asked to explain how it is possible that by moving our entire infrastructure to 10 bit color could possibly deliver both better quality images and give us more efficient (ie smaller) streams. We have been overhauling our delivery of 4K streams in an upcoming release of our engine and have moved the entire process to 10 bit. This not only allows us to provide a real time delivery of HDR10 streams, but also for SDR displays gives us better quality with smaller streams, saving delivery costs.

Initially when you think about adding more bits per pixel it makes sense that you get better image quality, but getting better efficiency doesn’t seem to make sense, and I’ve been asked “how is this possible”. By moving the entire workflow to 10 bit, we are able to compress with less errors. To deliver the best quality video possible, you want to have as few “errors” in the encoded version when comparing it to the original uncompressed version. The process by which an encoder reduces the file size is called quantization . Comparing the original image to the resultant image in compression there can be a difference of pixels , however that difference is unaffected by the depth of those pixels.

During the encoding process, a 10 bit image has roughly 20% more data to be compressed. During the hardest parts of encoding where there is high speed movement or large blocks of the screen ar changed, the higher bit rate allows for higher accuracy in recreating the original image thereby giving a better quality result. Since we have to encode at the same target bit rates, whether 8 bit or 10 bit, you end up with a better image at the same bit rates. This is mostly due to the underlying math that generates less errors in 10 bit than in 8 bit.

Given that our mastering process starts with an uncompressed 16 bit image of every frame, we can revisit the original master and rework it through the process using 10 bit target files instead of 8 bit for all displays, whether SDR or HDR and continue to improve the library. This is especially going to be noticed on SDR displays where banding shows up in the lower bit rates.

In an effort to further increase our network performance, reduce our startup times, and provide overall network efficiency in the upcoming release of UltraFlix 3.0 I’ve been doing a lot of research into alternative network protocols. UltraFlix 2.x currently uses https calls for it’s streaming, and while secure and stable, it can be improved upon. Given the scale we are now seeing closing in on a half million users, small improvements can yield big impacts especially on origin to edge performance which directly impacts startup times. For 3.0 we are testing the Quick UDP Internet Connect (QUIC) protocol.

QUIC supports a set multiplexed connections over UDP, and provides security protection on par with TLS/SSL. QUIC also provides reduced connection and transport latency by using a variable frame/packet size. QUIC uses bandwidth estimation in each direction providing congestion avoidance. It also times packet transmissions evenly to help reduce packet loss. The use of packet-level error correction codes also helps reduce the need to retransmit lost packet data, further improving performance. Finally, QUIC aligns cryptographic block boundaries with packet boundaries. This means that the impact of packet loss impact is mitigated.

With the goal of decreasing the buffering and setup time we are relying on some of the benefits found in QUIC, specfically the fact that QUIC handshakes typcially require zero roundtrips before sending payload, as compared to 1-3 roundtrips for TCP+TLS calls. In addition, we have crafted some proprietary techniques to the video stream that optimize the ability to quickly start the stream while buffering is still taking place, further reducing startup time on any bitrates, including the new UHD Blu-ray quality option that can be enabled on homes with > 50mbit internet connections.

I’ve been bombarded with questions today asking me about remastering of movies shot digitally. There are several issues when delivering a movie shot in digital to the consumer whether using DVD, Blu-ray or OTT streaming. These issues become greatly amplified when you start moving into the Ultra HD realm, especially with the various color space issues and HDR formats. With the consumer TV market HDR and UHD are not standard. Color space can be DCI-P3 or REC2020. HDR standards include HDR-10, DolbyVision, HLG and variations that TV manufacturers are implementing. Even within a single manufacturer you have sets that can generate different levels of brightness in HDR. You can have sets that max out at 500nits and others at 1,000 nits. When viewing video on the different levels of color and brightness you end up having a different threshold for the Flicker Fusion where the movement causes a visual flicker. On lower end panels this is much more noticable than higher end panels. It becomes really obvious when videos shot digitally at 50/60 fps is played back on sets that don’t support the higher frame rate and have to stepped down to 25/30 fps.

When preparing videos and movies to be streamed OTT you can improve the user experience substantially by creating different masters for various platforms from mobile phones to the highest end HDR Ultra HD television.

I had a conversation today with someone who was asking me about film remastering. His first question was “if a movie was shot in digital format, then you don’t have to do anything but encode it right?” While several movies are being shot in digital format, there is a long held belief by many in the industry that film provides a much better look and feel for movies. We first learned this when working on the Interstellar project where we had to review our compressed digital delivery along side the original film output. Directors all take great care in their art, and rightfully so, as it’s their expression to the world of story they want to show and tell. Some directors will even go as far as choosing the type of film that they shoot on to get a particular look. This attention to detail is something that we spent a lot of time on when working on The Good The Bad and The Ugly project as we not only were trying to recreate the directors vision of the film, but also to match the choices made in lighting and apply coloring techniques to recreate the style of the print.

There are several considerations that have to be made when delivering a movie to the consumer on a TV over the internet. First and foremost, we have to look at what can be done to optimize the number of bits that are being streamed while trying to retain the original vision of the movie. A typical stream is going to deliver 6 to 8 gigabytes of data, which has been compressed down from the original 4 to 7 terabytes of raw digital footage. There is a significant amount of data to remove in order to make that work.

There are many areas of remastering techniques that are used on both analog and digital masters. One area that we are currently doing a lot of experimentation with and seeing some great results is film grain. Film grain provides a unique look to a film and helps the video being shown to get away from that plastic look that is especially prevalent in modern video that is shot on high end digital sensors at 60 fps. While that look is really great for showing off the color and brightness of the latest generation 4K HDR television sets, it can be off-putting for a movie experience. This is where grain can be your friend. By having grain, film has a more natural and fluid look. Capturing that grain is your enemy however, when trying to create a compressed digital file to be streamed. Grain is realized in pixels as what appears to be random patterns of different variations in the lighting of textures within a scene. This typically wreaks havoc when you are trying to compress a scene as compression does really well when you have long stretches of the same colored pixels in a row and does far worse when there are lots of subtle variations. There are a lot of grain filters that can be used during the post production process that can take the digital images and make them appear move film like. Where we are doing a bunch of work is to add that filter post expansion on the client side within the player as opposed to upstream pre-compression. This allows us to gain a better compression ratio but still apply the same “look and feel” of the graining filter that was desired.

With new techniques and tools literally coming out every week, and new projects coming on board we have the fun job of both redoing movies we have previously remastered and compressed and applying the new methods to improve them as well as taking some of the latest and greatest state of the art digital movies and applying new methods to them to show even greater improvement. This job is sort of like the guys that paint the Golden Gate Bridge, it’s never done. By the time they get to one end, it’s time to go back and restart.

Some of the new cool technology we are playing with allows us to take an old trailer and a new source movie in 4K and the program will recut the trailer using the original scene cuts and finding them in the new source material and automatically re-create the new trailer.

I’m looking for some UltraFlix users that have a surround sound setup connected to their 4K TV willing to test some videos with various embedded surround sound streams. I’ll provide the movies at no charge for feedback on the sound delivery. email david@ntek.com if you would like to participate

Final testing this evening on a new update to the encoding engine, version 18.0 which includes updates for HLS/DASH fragmentation, multiple audio streams (2ch HyperAudio/Dolby/DTS), HDR10 color space. Adding a bunch of quality enhancements researched over the past two years including much better 360p, 480p, 720p and 1080p videos for mobile devices, AppleTV and Roku 3 boxes.

Also need to release for performance enhancements as it’s got over 1,400 movies in the queue to run through it once released.

As we prepare for the next generation of 4K Ultra HD content updates to the UltraFlix network we find ourselves amidst another format war. Remember when there was Beta and VHS. Beta was better and VHS still won out. We appear to be on the brink of a similar battle for the next generation of 4K TVs. While DolbyVision has superior color gamut (rec 2020 versus DCI P3) and is spec’d to a maximum of 10,000 nits versus 4,000 in HDR10, it currently appears that HDR10 is winning out with the TV manufacturers. One of the biggest issues on the content side is that you still have to go through Dolby to get your color work done, which can be a hindrance. Fortunately we’ve always started with a 16 bit color HDR master for everything we work on, so as it’s brought down through the process, and finally delivered over the internet to your TV it’s source material can always be revisited as the 4K Ultra HD space matures.

With HDR tv’s now becoming standard fare in the consumer space, remastering everything we have into HDR capable is the next task for the studio team. Exciting times as the home movie experience is now surpassing that of the movie theaters in terms of quality visuals.

I’ve had a lot of people ask us about our 4K content, and given the fact that all 4K TV’s have built in scaling hardware, who cares what the source is, that they can save money by renting a Blu-ray or watching a movie for free on Netflix or Amazon and it will be just as good. Fortunately for us, that is simply not true. We’ve put a lot of effort into taking what the studio delivers to us, and making sure that we provide the best version of that film to the consumer’s end viewing device, whether it be the greatest OLED TV from LG or an Android phone from T-Mobile. You must start with the greatest quality source material, and then work your way down to the pixels that arrive to the screen, trying to do as little damage as possible along the way to recreate a cinematic like experience. With UltraFlix we’ve been able to surpass the quality offered in many of the second tier cinemas, and we certainly far exceed the quality of content delivery from our streaming competitors.

What is even cooler for me is last night I was able to get a small peak into the future of Film restoration and remastering technology and it is really cool. I can’t wait to be part of the next generation of digital delivery of Movies and TV shows as it’s getting better and better every year.

I’ve included a couple of comparisons of movies that we have worked on at 4K Studios and Deliver through the UltraFlix network so you can see that the source of where you get your 4K does matter, and that simple scaling by a TV does not result in the same quality experience.

Robocop Comparison UltraFlix, HBO Go, Amazon

Charade UltraFlix remastered by 4K Studios vs Netflix

My Way remastered by 4K Studios and delivered by UltraFlix compared to Amazon